Cascara Sagrada

Botanical Description & Habitat

Rhamnus purshiana

Family
Anacardiaceae

Common Names

Bearberry	Bearwood
California buckthorn	Chittem bark
Christ's thorn	Holy bark
Persian bark	Sacred bark
Shittimwood

Habitat

Found in Europe and western Asia, and in North America, from northern Idaho to the Pacific coast; mountainous areas.

Related to the European Buckthorn.

Description

Cascara sagrada is a small deciduous tree growing from 15-20 feet in height. It has pubescent stems covered with reddish-brown bark and often, gray lichen. The tree bears dark green elliptic to oblong-ovate leaves with prominent veins and toothed margins. The leaves are rounded at the base and have somewhat hairy undersides. Short-stemmed clusters of small, greenish-white flowers grow from the upper leaf axils; they eventually produce black, pea-sized poisonous drupes.

Medicinal Parts

Bark - dried, collected at least a year before use.

Historical Properties & Uses

Cascara sagrada is perhaps the most common laxative used in both herbal medicine and orthodox pharmacy. It is technically classified as a stimulant laxative, since it induces peristalsis.

The active constituents of cascara are the anthraquinones. They are inactive in the gastro-intestinal tract until they reach the colon; there they produce a soft or formed stool within about six to eight hours and cause vigorous peristalsis.

One of the most common uses of cascara is to correct habituation to other laxatives by restoring intestinal tonus. In smaller amounts, the herb has proven effective in the treatment of liver disorders and gallstones. The anthraquinones have potent antibacterial properties; they have been used against leukemia and as immunosuppressants during skin graft operations.

Cascara constituents have also served as chelukemia and immunosuppressants during skin graft operations. Cascara constituents have also served as chelating agents in the prevention of urinary stones.

Cascara does not lose efficacy with repeated use. For the most part, cascara is non-addictive, and only really heavy abuse, which is rare, produces "cathartic colon." Normally, its main side-effect is griping. It may have other physiological effects as well, due to one or more of its numerous constituents (e.g., tri- and dihydrooxyanthraquinones--emodin, fragulin, iso-emodin, aloe-emodin, and chrysophaol--and rhein, and aloins).

This herb is approved by the German Commission E for constipation.

It has recently been found to inactivate enveloped viruses (e.g. herpes simplex). (Sydiskis, 1991)

References:

Blumenthal, M (Ed.): The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. American Botanical Council. Austin, TX. 1998.

Facts and Comparison. The Lawrence Review of Natural Products. May, 1996.

Sydiskis, RJ et al., Inactivation of enveloped viruses by anthraquinones extracted from plants. Antimicrob. Agents Chemother. 1991, 35(12):2,463.

Method of Action

The laxative properties of cascara are so well known as to require virtually no documentation. The active constituents ("cascarosides") are anthraquinones, or anthranol derivatives related to emodin. Inactive precursor glycosides are hydrolyzed within the lumen of the large bowel, having arrived by passage through the intestinal tract and by the hematogenous route following absorption in the small bowel. The active hydrolysis products then stimulate the large bowel in some unclear manner, perhaps by a direct stimulation of Auerbach's plexus.

A study using cascara to treat constipation in the elderly found the herb was tolerated extremely well by that age group. When supplemented with cianocobolamine and inositol, and improvement in blood levels of vitamin B12 was observed. This observation was considered very important because vitamin deficiencies are common in the elderly population.

The use of cascara to treat liver disorders and gallstones has received some experimental support. The aloe-emodin in cascara and other anthraquinone-containing herbs has antileukemia properties.

Anthraquinones have potent antibacterial properties against pathogenic intestinal gram positive and gram negative bacteria.

Emodin, rhein and related compounds demonstrate antibiotic activity by inhibiting the biosynthesis of nucleic acids and the respiration processes of bacteria.

Cascara constituents can serve as chelating agents to prevent the formation of calcium-containing urinary stones.

Drug Interactions & Precautions

Known Interactions

Due to its cathartic activity, cascara sagrada may potentiate anticoagulant therapy by reducing absorption of vitamin K from the gut. It may also inhibit absorption of dextrose from the intestines.

This cathartic herb increases intestinal transit time. Therefore, cascara sagrada may inhibit the absorption of digitalis glycosides, and decrease their cardiac action. Cathartic-induced hypokalemia, however, increases the toxicity and potency of absorbed digitalis, as well as potentiates muscle relaxants.

In addition to the specific interactions listed, the cathartic action of cascara sagrada tends to hasten the passage of all oral medications through the gut, thereby inhibiting their action.

Increased loss of potassium can potentiate cardiac glycosides and antiarrhythmic agents.

Possible Interactions

Laxative-induced diarrhea may result in decreased absorption of isoniazid. The same is true with sulfisoxazole, but this appears to be a clinically unimportant interaction effect.

Comments

Laxatives induce increased speed of intestinal emptying, which may result in decreased absorption of vitamin K and/or anticoagulants.

References:

Blumenthal, M (Ed.): The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. American Botanical Council. Austin, TX. 1998.

Safety Factors & Toxicity

Standard preparations of anthraquinone products, including cascara, senna and aloe, are safe even if consumed in enormous quantities. Chronic abuse produces a dark staining of the colon mucosa, which is of little consequence and will disappear after cessation, within a year. The function of the colon and rectum remain unimpaired.

Anthraquinones pass into the mother's milk with laxative effects on the baby.

Hypersensitivity, although rarely observed, is no problem in practice.

Other problems that might occur are inherent in the use of any cathartic, not just anthraquinones. These include: an appendix perforation in appendicitis, hypopotassaemia in daily use (as in a slimming program), and impaired resorption of digitaloids.

In humans, prolonged, excessive dosage of any laxative, including the anthraquinones, may cause metabolic disturbances which always accompany persistent diarrhea. The extreme effect of addictive purgation is the 'cathartic colon' in which loss of mysenteric plexus neurones, dilation and structural damage and marked hypokalemia occur. In normal practice, the only adverse reaction likely to be encountered from the use of therapeutic amounts of anthraquinone laxatives is griping.

This herb has approval status by the German Commission E.

The German Commission E recommends a limited duration for the use of this herb of not over 1 - 2 weeks without medical advice.

References:

Blumenthal, M (Ed.): The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. American Botanical Council. Austin, TX. 1998.

Preparation & Administration

Dried bark
fluid extract (1:1 in 25% alcohol), 2-5 ml at bedtime

This herb has approval status by the German Commission E.

Recommended daily dosages in Germany are as follows:

20 - 30 mg calculated as cascaroside.

References:

Blumenthal, M (Ed.): The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. American Botanical Council. Austin, TX. 1998.

Note: This Herbal Preparation information is a summary of data from books and articles by various authors. It is not intended to replace the advice or attention of health care professionals.

References

American Hospital Formulary Service. Am Soc of Hosp Pharm. Wash, D.C.

Anton, R. & M. Haag-Berrurier. Therapeutic use of natural anthraquinone for other than laxative action. Pharmacology, 20 (Suppl 1), 104-112, 1980. A Review.

Azarnoff, D.L. & A. Hurwitz. 1970. Drug interactions. Pharm Phys, 4(2). pp. 1-7.

Beckman, H. 1967. Dilemmas in drug therapy. Saunders, Phila. p. 102.

Blumenthal, M (Ed.): The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. American Botanical Council. Austin, TX. 1998.

Bressler, R., M.D. Bogdonoff & G.J. Subak-Sharpe. 1981. The Physicians Drug Manual. Doubleday & Co, Inc. Garden City, NY. 1213 pp.

Culbreath, David M. R. A manual of Materia Medica and Pharmocology. Eclectic Medical Publications, Portland, OR, l983.

Facts and Comparison. The Lawrence Review of Natural Products. May, 1996.

Fairbairn, JW & Simic, S: New dry extract of cascara (Rhamnus purshiana DC bark). J. Pharm. Pharmacol. 1970, 22:778.

Goodman, L.S. & A. Gilman. 1975. Pharm Basis of Thera. MacMillan, NY.

Hansten, P.D. 1979. Drug Interactions, 4th ed. Lea & Febiger, Phila.

Hansten, P.D. 1969. Oral anticoagulant drug interactions. Hospital Form. Management, 4(1). pp. 20-22.

Hyde, F.F. British Herbal Pharmacopoeia. British Herbal Medicine Association: West Yorks, England, 1983

Interactions of drugs. Med Let Drugs Ther, 12(11). pp. 93-96.

Kastrup, E.K., ed. 1981. Drug Facts and Comparisons, 1982 edition. Facts and Comparisions Division, J.P. Lippincott Co, Phila(St. Louis).

Kerhard, J. & Bouquet, A. Plantes Medicinales et Toxiques de la Cole d'Ivore, Haute-Vota, Vigot, Paris, 1950.

List, P. & L. Hoerhammer. 1969-1976. Hagers Hanbuch der Pharmazeutischen Praxis, vols. 2-5. Springer-Verlag, Berlin.

Marchesi, M, M. Marcato & C. Silvestrini. Esperienze cliniche con un perparato contenents cascara sagrada e boldo nella terapia della stipsi semplice nell'anziano. Giournale Clin. Med., 63(11-12), 850-863, 1982.

Martin, E.W. 1978. Drug Interactions Index, 1978/79. J.B. Lippincott Company, Philadelphia.

Mattila, M.J., et.al. 1974. Effect of sodium sulphate and castor oil on drug absorbtion from the human intestine. Annals of Clinical Research, 6. p. 19.

Mowrey, Daniel B., Ph.D. Exper. Psych., Brigham Young University. Director of Nebo Institute of Herbal Sciences. Director of Behavior Change Agent Training Institute. Director of Research, Nova Corp.

Prescott, L.F. Dec. 6, 1969. Pharmacokinetic drug interactions. Lancet, 2. pp. 1239-1243.

Sydiskis, RJ et al., Inactivation of enveloped viruses by anthraquinones extracted from plants. Antimicrob. Agents Chemother. 1991, 35(12):2,463.